Automatic line switch lock-out

ABSTRACT

The invention provides a control arrangement for an appliance and includes a switch and switch control mechanism associated with the door of the appliance which permits the door to mechanically control the electrical functioning of the switch through movement of the door between an open and closed position. The control mechanism includes a cam and linkage arrangement which positively prevents closing the switch until the door has been closed and which opens the switch when the door opens. Once the loading door has been closed, and the cam and linkage mechanism placed in a position to free the switch means, the switch means must then be manually actuated to an &#39;&#39;&#39;&#39;on&#39;&#39;&#39;&#39; position to provide for operation of the appliance with which it is used.

United States Patent Gorsuch 1 Sept. 5, 1972 [54] AUTOMATIC LINE SWITCH LOCK- OUT [72] Inventor: Harold F. Gorsuch, Mansfield, Ohio [73] Assignee: Westinghouse Electric Corporation,

' Pittsburgh, Pa.

[22] Filed: March 31, 1971 [21] Appl. No: 129,684

[52] US. Cl ..200/6L62, 34/45 [51] Int. Cl. ..H0lh 3/16 [58] Field of Search ..200/61 .62-61 .84;

[56] References Cited UNITED STATES PATENTS 3,602,662 8/1971 Hailer ..200/61 .62 3,440,373 4/1969 Blewitt ..200/61.7 1,564,207 12/1925 Cloud ..200/6l.8 2,858,619 11/1958 Hughes ..34/45 Primary Examiner-Robert K. Schaefer Assistant Examiner-M. Ginsburg Att0rney-F. H. Henson, E. C. Arenz and R; B. Farley [5 7] ABSTRACT The invention provides a control arrangement for an appliance and includes a switch and switch control mechanism associated with the door of the appliance which permits the door to mechanically control the electrical functioning of the switch through movement of the door between an open and closed position. The control mechanism includes a cam and linkage arrangement which positively prevents closing the switch until the door has been closed and which opens the switch when the door opens. Once the loading door has been closed, and the cam and linkage mechanism placed in a position to free the switch means, the switch means must then be manually actuated to an on position to provide for operation of the appliance with which it is used.

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PATENTEDSEP 51912 SHEET 2 0F 2 FIG. 5.

FIG. 3.

BACKGROUND OF THE INVENTION Field of the Invention DESCRIPTION OF THE PRIOR ART ruption of the circuitry which actuated the unit in its operation. Normally, this was accomplished by a switch being disposed so as to be spring loaded to an off position with the door open and to be moved to an on position upon reclosing of the loading door for the appliance. Such an arrangement provided a convenient mechanism for interrupting the operation when the operator desired to either terminate its operation or desired to open the door for some reason such as to observe its operation, to add additional clothes to the appliance, or to reposition the clothes contained therein. Such a door switch was generally satisfactory; however, its inherent safe operation could be easily intentionally defeated by mere manual depression of the door switch by the user. Further, in the event that a child, for example, crawled into the unit and then closed the door, the appliance would be in a condition for operation if the main switch had been previously actuated. It appeared advantageous, therefore, to provide for a washer or dryer door actuated switching arrangement which required that the door of the appliance first be closed and then a supplemental manual effort be required to reactuate the appliance after its temporary termination by opening of its loading door.

Such an arrangement is shown in US. Pat. No. 2,858,619 wherein a speed responsive switch is coupled to the drive motor and opens upon deenergization of the motor, which, in turn, is deactivated by opening a door actuated switch. Subsequent closing of the door then recloses the door switch but a supplementary switch also must be manually actuated to short out the speed responsive switch and held closed until the motor has attained sufficient speed to reinitiate the dryer circuit through the speed responsive switch. This arrangement provides a convenient system for the requisite additional manual actuation step; however, its inherent safety can still be intentionally defeated by manually closing both the door switch and the supplemental switch whereupon the appliance could be operated while the door was in an opened position. Accordingly, it would be advantageous to provide a switch for a dryer or other appliance that, in addition to the required supplemental manual effort after closing of the appliance door, was positively prevented from being manually actuated whenever the door was not closed and thereby its safe operation could not be defeated.

SUMMARY OF THE INVENTION The invention provides a control arrangement utilizing a linkage and cam mechanism which prevents operation of a switch until the door of the appliance is fully or substantially fully closed and only then permits the required additional manual manipulation of the switch to place the appliance in an operative, active condition. The switch contains an actuating plunger, one end extending outwardly towards the front of the appliance for engagement by the operator and the other end extending inwardly towards the cam and linkage mechanism. Initial opening of the appliance loading door places the switch in an opened, off condition so that operation of the appliance is interrupted. Such interruption is occasioned by movement of a linkage mechanism which extends between a hinge on the loading door to a camming mechanism which pushes the inwardly extending plunger end to move the switch to its open position. While the door remains open, the cam and linkage mechanism positively prevents manual movement of the outwardly extending plunger end by maintaining engagement with the inwardly extending end so that the switch cannot be closed. Closure of the loading door causes the cam mechanism to move away from engagement with the inner end as dictated by the relationship of the linkage mechanism with the hinge so that the outer end of the switch plunger may be,

manually depressed to place the appliance in an operative, active condition.

In one embodiment of the invention, movement of the door to an open position causes a cam surface associated with the door hinge to rotate. A rocking type lever provides one arm having a cam following element which follows the cam surface and places the oppositely extending arm of the lever against the inner end of the plunger of the switch to move the switch to an open position. The cam is contoured so that whenever the door is open the lever is maintained against the plunger thereby positively preventing manual depression at the outwardly extending portion of the plunger. Once the door has been closed, the inner end of the plunger is free of the lever and the manually accessible end can be depressed to activate the appliance.

In another embodiment of the invention the hinge for the door actuates a hinge linkage including a crank member to provide generally linear movement of a cam member to abut the inner end of the switch plunger urging it to an open, off condition and positively prevents the plunger from being moved to close the switch until the door has again been fully or substan tially fully closed.

DRAWING DESCRIPTION For a better understanding of the invention, reference may be had to the preferred embodiments, exemplary of the invention, shown in the accompanying drawings, in which:

FIG. I is a front elevational view of an appliance embodying the invention;

FIG. 2 is a view taken along line IIII of FIG. 1;

FIG. 3 is a view similar to FIG. 1 showing an alternate embodiment of the invention;

FIG. 4 is a view taken on line IV-IV of FIG. 3; and,

FIG. 5 is a view of the internal operating components of the switch.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring specifically to FIGS. 1 and 2, the appliance shown therein may be a clothes washer or dryer, or the like, including a cabinet having a hingedly mounted door 12 with a handle 14. The door is mounted for movement between open and closed positions by hinge means including hinge plates 16 secured to the door. Each hinge plate 16 has affixed thereto a hinge pin 22, 24 which rotates with the door and is pivotally supported in aligned bores of journalling brackets 18 secured to an inner wall portion of the cabinet.

In the embodiment of the invention illustrated in FIGS. 1 and 2, a switch 34 is mounted on the inside of the cabinet 10, and a switch control and blocking mechanism 26 comprising a cam disc 28 and a rocking type lever arm 42. The switch 34 has an insulating housing 36, and an operating member 56 in the form of a plunger, one end of which protrudes outwardly from the cabinet 10 through an opening formed therein, and

the opposite end54 of which extends from the switch housing 36 inwardly of the cabinet 10. The cam disc 28 of the switch control and blocking mechanism is secured to an upward extension of hinge pin 24 for rotation with the latter, and the lever arm 42 is generally medially supported on the switch housing 36 by means of two parallel legs straddling the housing 36 and pivotally mounted thereon by journalling pin 38. The lever arm 42 has one end defining cam follower 46 with a generally V-shaped portion 48 which cooperates with the cam disc 28, while the opposite end provides a switch contacting portion including an adjustable abutment member 50 cooperable with the inwardly directed end 54 of the switch plunger 56. As shown in FIG. 2, member 50 includes a screw which is adjustable relative to the operating plunger 56 of the switch 34.

In FIG. 2, the various parts are shown in positions which they occupy when the door 12 is closed and the switch 34 is still open. Thus, in the fully closed position of the door, a minor or releasing cam surface of the cam disc 28, formed by a generally V-shaped notch 32, is aligned with the cam follower portion 48 to allow the lever arm 42 to remain in a position in which its switch contacting portion including abutment member 50 will not interfere with a manual operation of the switch plunger 56 to its enabling or on position, ie with movement of the plunger 56 toward the part 50. The remaining part of the circumference of the cam disc 28, extending from oneside of the notch 32 to the other, represents a major or locking cam surface which, upon movement of the door from its fully closed position, first causes the cam follower to be cammed out of the notch 32, thereby causing abutment member thereof to engage the switch plunger 56 and to move it to its disabling or off" position shown in FIG. 2, and then remains aligned with the cam follower portion 48 so as to maintain abutment member 50 in blocking engagement with the switch plunger 56, thereby positive ly preventing manual depression of the latter to its on position for as long as the door is in any position other than at least substantially fully closed. Only upon return of the door to such substantially closed position will the cam disc 28 be rotated to align its low or minor cam surface 32 with the cam follower portion 48, thereby to allow the contacting portion to release the switch plunger 56 for manual operation thereof to its on position.

Referring now to FIGS. 3 and 4, the embodiment shown therein again includes a switch 34 mounted on the inside of the cabinet and connected in circuit with the drive motor (not shown) of the machine, and a switch control and blocking mechanism operatively connected to the hinge pin 24'. However, in this embodiment, the switch 34 is at a location generally remote from the hinge structure of the door, and the switch control and blocking mechanism comprises a slide member and link means 74 operatively connecting the slide member 80 to a crank 70, 72 on the hinge pin 24, the link 74 being pivotally connected at one end thereof to the crank portion 72 and, at its other end, extending through an opening 82 in an end flange 84 of the slide member 80 and terminating in a bent portion 76 engaged with an aperture 78 formed in the slide member adjacent its end flange 84. The slide member 80 has two mutually offset portions 96 and 98 joined by cam surface 100, and it is supported, adjacent the inward end 54 of the switch plunger 56, for sliding movement generally in a plane normal to the axis of movement of the plunger 56. In the embodiment shown in FIG. 4, sliding support for the slide member 80 is provided by a stationary guide member 86 secured to the housing of the switch 34 and having two flange portions 88 and 90 provided with guide slots 92 and 94 for the slide member 80. In order to compensate for manufacturing tolerances, the link 74 may be provided with a kink 102 of such dimensions as may be necessary to ensure proper positioning of the cam member 80 relative to the plunger 54, 56 upon movement of the door 12 to and from the fully closed position thereof.

FIG. 4 shows the parts in the positions occupied when both the door 12 and the switch 34 are closed. Upon movement of the door from its closed position, the crank 72 on the hinge pin 24, acting through the link 74, will move the slide member 80 in a direction, i.e., to the left as viewed in FIG. 4, causing the cam surface to cam the switch plunger 56 to its disabling or off" position, and causing the slide portion 96, which is nearer the plunger than the slide portion 98 and functions as a blocking portion, to be placed into blocking engagement with the plunger so as to positively prevent manual operation thereof to its on position. Upon closure of the door 12, the hinge pin 24' together with its crank 72 will rotate to effect movement of the slide member 80 in the opposite direction, i.e., to the right as viewed in FIG. 4, until the blocking portion 96 and the cam surface 100 thereof clear the end 54 of the switch operating plunger 56, thereby releasing the latter for manual depression to its on" position.

The switch 34 may be any suitable bistable switch, preferably of a snap-action type, having a stable on" and a stable off position for enabling and disabling the drive motor (not shown) of the machine. As illustrated in FIG. 5, showing only the base 52 of the switch housing 36 with the switch parts assembled therein, the door-operated switch 34 utilized in the embodiments described above is a commercially available general purpose snap-acting microswitch type PL and includes a substantially stationary terminal leaf conductor 58 extending through one end wall of the switch housing 36 into a cavity 53 formed therein, a pair of substantially stationary terminal leaf conductors 60, 64 extending in substantially parallel relation to one another through an opposite end wall of the housing 36 into the cavity 53 and carrying contacts at their inner ends, and a movable contact leaf 62 pivotally supported at one end thereof on the inner end of the terminal leaf conductor 58 and carrying at its other end contacts which are movable alternatively into engagement with the contact on the one or the other of the two terminal conductors 60 and 64. Movement of the contact leaf 62 is effected, with a snap-action, by means of an overcenter spring 66 which has its opposite ends connected to the stationary terminal conductor 58 and the contact leaf 62, and which extends through an opening in the stem of the operating plunger 56 so that movement of the latter in opposite directions will shift the line of spring action to opposite sides of the pivot axis of the contact leaf 62, thereby causing the latter to pivot with a snap action in the direction in which the line of spring action is shifted. Thus, manual depression of the plunger 56 will cause the spring leaf 62 to snap into engagement with the contact on terminal conductor 60, and actuation of the plunger 56 by the cam follower 42 (FIG. 2) or the slide member 80 (FIG. 4) will cause the spring leaf 62 to snap into engagement with the contact on the terminal conductor 64, it being understood, although not shown, that in the operational machine, the terminal conductors 58 and 60 of the switch 34 would be serially connected in circuit with the drive motor (not shown), and terminal conductor 64 could be connected otherwise, e.g., to a signal device, such as a lamp (not shown), giving an indication when the door 12 is not fully closed. Of course, the terminal conductor 64 could also be omitted, if desired, and replaced with a simple stop (not shown) defining the off position of the contact leaf 62.

From the foregoing, it will be appreciated that the invention has provided a control arrangement for safe energization of an appliance which affords several distinct advantages. First, it acts positively, rather than through spring bias, in moving the switch 34 to its open position so that sticking of the switchin its on position cannot occur. Second, at maintains the switch positively blocked in its off position for as long as the door is not at least substantially fully closed so that inadvertent as well as intentional starting of the machine is rendered impossible while the door is in an open position. Third, it does not automatically close the switch upon closing of the door so that the operator of the machine must make a conscious effort to start the machine by manually closing the switch which, of course, makes it impossible for a child having crawled into the machine to start the latter simply by closing the door. And, fourth, it allows the switch to be located in a position generally remote from the door such that manual operation thereof is possible only from without the cabinet, thereby again definitely eliminating the danger of a child crawling into the machine and then starting the latter by depressing a switch within the childs reach.

What is claimed is:

l. A control arrangement for an appliance having a cabinet including a door and hinge means for mounting said door thereon, said control arrangement comprismg:

a switch fixedly mounted within said cabinet including a switch operating member movable to an on position, permitting energization of said appliance and an off position preventing energization of said appliance, said member having a portion extending through said cabinet irrespective of the position of said door for manual operation thereof; and

means movably mounted within said cabinet for positively blocking said switch operating member to be manually moved to said on position, said blocking means moved from a non-obstructing position with respect to said member to an obstructing position with respect to said member in response to said door being moved from at least a substantially fully closed position to an open position, respectively, said blocking means including means moving said switch operating member from said on" position to said off position in response to movement of said door from said substantially fully closed position, whereby,

said door must be in at least said substantially fully closed position to permit manual movement of said switch operating member to said on position, and movement of said door to any further open position results in said switch operating member positively maintained in said off position.

2. The control arrangement of claim 1 wherein said blocking means includes:

a cam surface mounted for rotation in accordance with the rotation of said door, said cam surface defining a generally constant major surface having a depressed minor portion; and

a lever arm medially mounted for pivotal movement, one end of said lever arm defining a cam follower in contact with said cam surface and the opposite end of said lever arm defining a blocking portion generally adjacent said switch operating member, whereby alignment of said minor portion of said cam surface with said cam follower corresponding to said door closed position permits pivotal movement of said blocking portion of said lever and manual movement of said switch operating member whereas alignment of said cam follower with any portion of the major cam surface as through rotation of said door to an open position places said blocking member in a blocking position with respect to said switch operating member preventing manual movement thereof.

3. The control arrangement of claim 2 wherein:

said hinge means includes a hinge pin rotatable with said door; and,

said cam surface is provided by a cam disc having a generally circular circumference defining said major surface and a V-shaped notch in said circumference providing said minor portion.

4. The control arrangement according to claim 3 wherein:

said switch comprises a snap acting switch; and,

said switch operating member comprises a plunger defining an outwardly projecting end protruding from said cabinet and an inwardly projecting end facing said blocking portion of said lever arm, whereby,

movement of said plunger inwardly places said switch on and movement of said plunger outwardly places said switch in an off condition.

The control arrangement according to claim 4 wherein said switch operating member is moved from said on position to said off position by said blocking portion as said cam follower is forced from the minor portion of the cam surface to the major portion in accordance with the door being moved to an open position.

6. The control arrangement of claim 1 wherein said blocking means includes:

a crank arm mounted for rotation in accordance with the rotation of said door;

a link mechanism having one end engaging said crank arm and the opposite end slidably received within a bracket member whereby rotation of said crank arm imparts reciprocatory movement of said link mechanism;

said link mechanism further supporting two mutually offset surfaces each selectively movable in response to reciprocation of said link mechanism to a position generally adjacent said switch operating member, whereby disposition of one offset surface adjacent said member corresponds to said door closed position and permits manual movement of said member and disposition of the other of said ofi'set surface adjacent said member corresponds to a door open position and prevents manual movement thereof.

7. The control arrangement of claim 6 wherein said mutually offset surfaces are interconnected through a camming surface whereby said switch operating member is carnmed from said on position to said off position by said camming surface as said mutually ofiset surfaces are moved from said one offset surface adjacent said member to said other offset surface adjacent said member. 

1. A control arrangement for an appliance having a cabinet including a door and hinge means for mounting said door thereon, said control arrangement comprising: a switch fixedly mounted within said cabinet including a switch operating member movable to an ''''on'''' position, permitting energization of said appliance and an ''''off'''' position preventing energization of said appliance, said member having a portion extending through said cabinet irrespective of the position of said door for manual operation thereof; and means movably mounted within said cabinet for positively blocking said switch operating member to be manually moved to said ''''on'''' position, said blocking means moved from a nonobstructing position with respect to said member to an obstructing position with respect to said member in response to said door being moved from at least a substantially fully closed position to an open position, respectively, said blocking means including means moving said switch operating member from said ''''on'''' position to said ''''off'''' position in response to movement of said door from said substantially fully closed position, whereby, said door must be in at least said substantially fully closed position to permit manual movement of said switch operating member to said ''''on'''' position, and movement of said door to any further open position results in said switch operating member positively maintained in said ''''off'''' position.
 2. The control arrangement of claim 1 wherein said blocking means includes: a cam surface mounted for rotation in accordance with the rotation of said door, said cam surface defining a generally constant major surface having a depressed minor portion; and a lever arm medially mounted for pivotal movement, one end of said lever arm defining a cam follower in contact with said cam surface and the opposite end of said lever arm defining a blocking portion generally adjacent said switch operating member, whereby alignment of said minor portion of said cam surface with said cam follower corresponding to said door closed position permits pivotal movement of said blocking portion of Said lever and manual movement of said switch operating member whereas alignment of said cam follower with any portion of the major cam surface as through rotation of said door to an open position places said blocking member in a blocking position with respect to said switch operating member preventing manual movement thereof.
 3. The control arrangement of claim 2 wherein: said hinge means includes a hinge pin rotatable with said door; and, said cam surface is provided by a cam disc having a generally circular circumference defining said major surface and a V-shaped notch in said circumference providing said minor portion.
 4. The control arrangement according to claim 3 wherein: said switch comprises a snap acting switch; and, said switch operating member comprises a plunger defining an outwardly projecting end protruding from said cabinet and an inwardly projecting end facing said blocking portion of said lever arm, whereby, movement of said plunger inwardly places said switch ''''on'''' and movement of said plunger outwardly places said switch in an ''''off'''' condition.
 5. The control arrangement according to claim 4 wherein said switch operating member is moved from said ''''on'''' position to said ''''off'''' position by said blocking portion as said cam follower is forced from the minor portion of the cam surface to the major portion in accordance with the door being moved to an open position.
 6. The control arrangement of claim 1 wherein said blocking means includes: a crank arm mounted for rotation in accordance with the rotation of said door; a link mechanism having one end engaging said crank arm and the opposite end slidably received within a bracket member whereby rotation of said crank arm imparts reciprocatory movement of said link mechanism; said link mechanism further supporting two mutually offset surfaces each selectively movable in response to reciprocation of said link mechanism to a position generally adjacent said switch operating member, whereby disposition of one offset surface adjacent said member corresponds to said door closed position and permits manual movement of said member and disposition of the other of said offset surface adjacent said member corresponds to a door open position and prevents manual movement thereof.
 7. The control arrangement of claim 6 wherein said mutually offset surfaces are interconnected through a camming surface whereby said switch operating member is cammed from said ''''on'''' position to said ''''off'''' position by said camming surface as said mutually offset surfaces are moved from said one offset surface adjacent said member to said other offset surface adjacent said member. 